[Abstract Title]. - Society for Neuroscience

Topic: D.06.d. Saccades and Pursuit
Support: NIH Grant EY06069
RR 00165
Title: Information processing in parallel cortical-brainstem pathways for smooth pursuit
Authors: *M. J. MUSTARI 1,2 , S. ONO 1,2 , V. E. DAS 1,2 ;
1 Neurol., Emory Univ., Atlanta, GA; 2 Div. of Sensory-Motor Systems, Yerkes Natl. Primate Res.
Ctr., Atlanta, GA
Abstract: Smooth pursuit eye movements are used to maintain the image of a moving object
relatively stable on or near the fovea. The smooth pursuit system therefore must decode visual
motion and create commands for eye movements. This visual-oculomotor transformation
involves cortical, brainstem and cerebellar regions that carry complimentary signals for
supporting volitional smooth pursuit. We have examined information processing related to
smooth pursuit in different cortical areas including frontal eye field (FEF), middle temporal
(MT) and medial superior temporal (MST). Signals in the cortical pursuit system influence the
cerebellum through the dorsolateral pontine nucleus (DLPN), nucleus reticularis tegmenti pontis
(NRTP) and pretectal nucleus of the optic tract (NOT). We used multiple linear-regression
modeling to estimate the relative sensitivities of cortical (MT, MST, FEF), pontine (NRTP,
DLPN) and pretectal nucleus of the optic (NOT) neurons to eye-motion parameters (position,
velocity and acceleration) and retinal-error parameters (position, velocity and acceleration)
during step-ramp smooth pursuit of macaques (Macaca mulatta). We found that a large
proportion of pursuit-related MST and DLPN neurons primarily code eye-velocity information.
Similarly, a large proportion of FEF and rostral NRTP neurons code eye-acceleration
information. In contrast, foveal/parafoveal NOT neurons are most sensitive to retinal image
velocity. Anatomical studies indicate that the FEF-NRTP pathway selectively targets the vermis,
MST-DLPN pathway targets the ventral paraflocculus and MT-NOT pathways target the
flocculus and ventral paraflocculus. Therefore, parallel channels of information originating in
occipital, parietal and frontal cortical areas influence different regions of the cerebellum to
initiate, maintain and adjust volitional smooth pursuit.
Disclosures: M.J. Mustari , None; S. Ono, None; V.E. Das, None.
Poster
264. Eye Movements: Smooth Pursuit
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 264.9/DD26